Tribute to Valentine Telegdi

who passed away on April 8th in Pasadena

by K. Freudenreich, ETHZ/IPP/LHP Plenary CHIPP Meeting, PSI, October 2, 2006 Val Telegdi: years 1922 - 1943

Born on January 11th, 1922 in Budapest, spent only a few years in Hungary. According to his own words in his younger years he was a master of “involuntary tourism” , participating passively in German occupations in three countries: Austria, Belgium and Northern Italy. He attended grammar school in Vienna and then a technical school in Brussels. From 1940 - 1943 he worked in a patent attorney’s office in Milan. He used to say that - contrary to Albert Einstein in Berne - being on the other side of the fence he really had to work hard. When the Germans occupied Northern Italy Val, together with his mother, fled to Switzerland. October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 1/20 Val Telegdi: years 1943 - 1946

After a short internment in a refugee camp he joined his father in Lausanne where he studied chemical engineering at the EPUL with a grant from the F onds Europ´een de Secours aux Etudiants. At the EPUL he also attended lectures in theoretical physics given by E.C.G. Stuckelberg¨ von Breidenbach whom he estimated very highly. Ironic telegram by Gell-Mann to “congratulate” Feynman for his Nobel prize: “Now you can give back my notes”, signed Stuckelberg¨ Stuckelberg¨ helped Val to be accepted by P. Scherrer at ETHZ.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 2/20 Val Telegdi: years 1946 - 1951

In 1946 the institute of physics was located at the Gloriastrasse. He got half the salary of an assistant (260,- SF/month, the rent for his furnished room being 40,- SF/month) His thesis advisers were P. Scherrer and W. Pauli as second reviewer. Pauli was feared because of his critical remarks on everybody, except on his teacher A. Sommerfeld. Also Scherrer had links to Sommerfeld, studies in Konigsberg,¨ P. Debye. Val had started to read Sommerfeld’s book on atomic structure and spectral lines at the age of 15 =⇒ his interest in Sommerfeld. Another important person for Val in Zurich¨ was Mario Verde, a theoretician. He was his friend, mentor, example and best man to his marriage with Lia, born Leonardi.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 3/20 Val and Lia: 1950 - 2006

Lia was very important to Val in many aspects: One aspect - fortunately, I had the honour to experience it quite often - are her exceptional cooking skills. On one occasion V. Weisskopf came back from Vienna to Val’s home with a Sacher Torte (tart). When comparing it to Lia’s Torte everybody found Lia’s much superior.

I would like to mention also Lia’s intelligence and charm, often smoothing out frictions.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 4/20 Lia Telegdi

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 5/20 Val Telegdi: years 1946 - 1951

Val was given a thesis subject using emulsions: Investigation of the photodisintegration of 12C into three Alpha Particles. For this purpose he used the 32 MeV Betatron at the Kantonsspital. There he met R. Wideroe.¨ Another person who - according to him - had been forgotten in Stockholm. Finally, it was luck that he was given work using emulsions while his PHD colleagues were doing - more respectable - hardware. Later in Chicago, he used this emulsion technique - together with J. Friedman - to investigate parity violation in the π − µ decay.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 6/20 Val Telegdi: years 1951 - 1976

In the fifties the university of Chicago was the Mecca of physics. Val made an application to E. Teller for a job but he was refused. Then a miracle happened - according to Val: V. Weisskopf asked him what he wanted to do after his doctorate. Val’s answer: if Switzerland is too small for Swiss physicists then this is more than ever true for myself. V. Weisskopf tried to find a position for Val at MIT in vain and recommended him then to Fermi. In 1951 Val was hired as instructor for one year at the University of Chicago, where he stayed till 1976, climbing up the career ladder till he became in 1972: ”Enrico Fermi Distinguished Service Professor”.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 7/20 Val Telegdi: years 1951 - 1976

Val’s senior colleagues in Chicago were: Chandrasekhar, Fermi, Maria Goeppert-Mayer, Teller, Urey and Wentzel. Among the “young Turks” were Garwin, Gell-Mann, Goldberger and later Friedman. Val called the time in Chicago the “quarter century which saw the most turbulent developments in particle physics” He once wrote that it was a time when even an ordinary physicist could make seminal discoveries. To judge the importance of the experiments listed in the following it should be noted that they were all answering the key questions of their time.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 8/20 Val Telegdi: years 1951 - 1976

One of the original P-violation experiments, using emulsions to study + + + π → µ + νµ, µ → e + νe +ν ¯µ.(1957) Proof of V – A in the decay of free polarized neutrons.(1957) 0 The mixed-strangeness property of the KL.(1958) The well-known BMT equation.(1959) Hyperfine effects in muon capture.(1961/62) Hyperfine effects in muonium → precise value of α. (1970/71) 0 0 KL → KS regeneration on electrons yielding a mean electromagnetic radius for neutral kaons etc. (1978)

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 9/20 Visits to CERN during the Chicago time.

During his time in Chicago he made frequent visits to CERN in the summer. Together with G. Charpak, F.J.M. Farley, R.L. Garwin, T. Muller, J.C. Sens and A. Zichichi he did the first measurement of the anomalous magnetic moment of the muon - the so-called g - 2 experiment - at CERN (1961) → picture.

At the ISR he participated in the R603 experiment which measured diffractive dissociation. He made significant contributions to the recoil spectrometer → picture.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 10/20 Construction of the g-2 µ storage ring

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 11/20 View of the R603 experiment

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 12/20 Val Telegdi: years 1976 - 2006

In 1976 Val returned to Europe. He became professor of Physics at ETHZ. Together with Hans Hofer he founded the Laboratory for High Energy Physics. In Zurich¨ he had a group working on atomic physics experiments and a group at PSI working on muon physics. At CERN he initiated the NA10 experiment which did a precise study of dimuon production by pions on nuclei → picture. A colleague of Val said that Val’s wave function had three peaks: one located in Zurich,¨ one in Geneva and one at Caltech where Lia and Val spent most of their winters.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 13/20 View of the NA10 experiment

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 14/20 Val Telegdi: years 1976 - 2006

From 1978 - 1981 he was member and from 1981 - 1983 chairman of the CERN Scientific Policy Board at a time when LEP was being established. Although the ETH group had opted for the ALEPH experiment he “convinced” us to join the L3 experiment → picture.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 15/20 View of the L3 experiment

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 16/20 Val Telegdi’s honours and distinctions

In 1991 he shared the Wolf prize with M. Goldhaber for their separate seminal contributions to nuclear and particle physics, particularly those concerning the weak interactions involving leptons. In 1995 he got the E. Lilienfeld prize “for his ingenious experiments to determine the characteristics of the elementary particles, for his discoveries concerning the nature of the weak forces as revealed by the capture and decay of muons, for his rigorous analysis of particle interactions, and for his ability to inspire and enlighten diverse audiences.” Val was member of many scientific societies: In the following only the countries are listed: France, Germany, Great Britain, Hungary, Italy, Russia, Sweden and USA. The following picture shows Val when he received the medal of foreign member of the Russian Academy of Science in June 2000. October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 17/20 Maiani + Telegdi + Shrinsky

Val receives the medal of foreign member of the Russian Academy of Science.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 18/20 Val Telegdi’s proposals for ETH -Perestroika

Lectures for PhD students instead of autodidactic training. In the lectures: less material, more compulsory exercises - students instead of listeners. Quantum Mechanics for experimentalists, not just an examination item but requisite know-how. Examinations at the end of each semester and not piling up a stock of knowledge. Discussions in the department about the contents of the lectures.

More “glasnost” in appointments of professors.

October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 19/20 Val Telegdi

We lost a Great Physicist. October 2, 2006, Plenary CHIPP Meeting, PSI, K. Freudenreich, ETHZ 20/20